Embodiments of the inventive concepts disclosed herein are generally directed to head-tracking systems and methods for providing georeferenced head position and/or orientation data.
Head worn displays (HWDs) with head-tracking systems are used in a variety of aircraft and ground vehicle applications to provide situational awareness information to pilots or other users. Georeferenced head-tracking determines the position and/or orientation of the head relative to the Earth, which enables display of symbology and imagery superimposed over the view of the scene. The potential improvement in situation awareness that can be provided by an augmented vision system is largely dependent on the accuracy and responsiveness of the head-tracking subsystems.
Georeferenced head-tracking is an important and challenging head-tracking function in head-worn display systems. Systems in the past have used a two-step approach, using a platform referenced head-tracking system whose output is mathematically combined with the position and orientation of the platform to compute an estimate of the head position and orientation referenced to the Earth. This approach is subject to accumulation of errors and time delay (latency) from the multiple sources, which degrades the accuracy and responsiveness of the output.
The accuracy, update rate, latency and jitter requirements for head-tracking systems for flight deck applications are challenging. Some existing solutions rely on various combinations of magnetic, optical and inertial tracker subsystems to attempt to meet these requirements. In spite of years of investment and effort, the performance of existing head-tracking systems is still in need of improvement.